


An Extella Special Halloween

by Varewulf



Series: SE.RA.PH. At Peace [10]
Category: Fate Extella, Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: Altera the Santa, Artoria Archer, Brave Elizabeth, Fluff, Gen, Halloween, MHX Alter - Freeform, Mordred Rider, Nero Caster, Silly, Tamamo Lancer, alternate classes, secret guest appearance
Language: English
Status: Completed
Published: 2018-10-30
Updated: 2018-10-30
Packaged: 2019-08-10 22:33:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,667
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16463645
Author URL: https://archiveofourown.org/users/Varewulf/pseuds/Varewulf
Summary: Had a goofy idea for a special Halloween fic for the Fate Extella/GO girls, which turned into a goofy fic.The class changed heroes have to brave a haunted castle to defeat the undead, and recover a legendary treasure! A quest of epic proportions. Kinda.





	An Extella Special Halloween

**Author's Note:**

> I have other things to write, but the idea for doing a Halloween thing with the girls I've added to my Extella series popped up, and then I wanted to get it done by Halloween... so yeah, here we are. The idea came after seeing the art for Brave Elizabeth, then remembering that Nero has a Caster version, and Tamamo has a Lancer version. It kinda snowballed from there.
> 
> Artwork chosen to best reflect what they're wearing here, not necessarily based on what the "best" art is. So while I've gone with all official artwork, I haven't gone for the stage 4 art except in a couple of cases where that better reflects how they've dressed up. (I hope all the links work)
> 
> Decided to go different/original with the Jeannes though, so no art for those, I'm afraid.

With the spooky times descending upon SE.RA.PH., a certain musical duo had approached Kishinami Hakuno to ask about doing something special for Halloween. They had the idea to go on a quest, but with a twist. Hakuno thought it sounded amusing, and agreed to help out.

The two quickly became three, and then more joined up, or were corralled into joining up, until most of the palace residents came along. In addition to that, the Moon Cell was petitioned to allow everyone a temporary class change to go with them dressing up and such. And to create a location for their quest to take place.

The costumes and classes were kept secret from Hakuno until the day was upon them, and she showed up to inspect them before they headed off. As she arrived, she couldn't help sensing a theme among most of the attendees.

"[Brave Saber Elizabeth Bathory](https://varewulf.files.wordpress.com/2018/10/brave-saber-elizabeth.jpg) is here to save the day!" Elizabeth declared, thrusting her sword into the air.

While not exactly the kind of outfit she'd normally expect of a Saber, it was absolutely something Hakuno could imagine Nero wearing. Speaking of...

"[Esteemed Caster Nero Claudius](https://varewulf.files.wordpress.com/2018/10/swimsuit-nero.jpg) will reduce her enemies to ash!" Nero sounded immensely proud of herself. As usual.

"Uh... Sa- Nero, what are you wearing?" Hakuno had to ask.

"Do you like it, Praetor?" Nero beamed.

"Sure, but... it doesn't exactly seem seasonal," Hakuno pointed out.

"Umu, umu." Nero nodded. "Well, you see, after Elizabeth showed me her costume, I figured I should also go in a bikini."

"I see..." Hakuno felt like there was some difference between bikini armour and just an actual bikini, but it didn't feel worth it to try to argue the point.

"And look, with the straps like this, you could fit your head up between my glorious breasts, Praetor!" Nero tugged dangerously at the straps containing her bosom, looking very proud at her idea. Sure, it looked like they provided enough leeway and stretch that it should be theoretically possible, but it seemed hazardous nonetheless.

"Ahem." A certain fox cleared her throat. "[Tamamo Lancer](https://varewulf.files.wordpress.com/2018/10/tamamolancer4.png) is on the scene, ready to impale any evil that stands in our way," Tamamo said, setting the butt of her 'lance' against the ground. "What do you think, Husband~? You're free to place your head between my breasts as well~." She practically purred.

"Mu... your bikini top would snap," Nero said curtly.

"I wouldn't mind, so long as our Husband didn't." Tamamo sounded like she was at peak chirpiness.

"So... the three of you have just switched roles?" Hakuno asked. It wasn't so much a new change, as a shift in positions. Though it made her wonder where that left her, as she had dressed like a vampire. Black cloak, stylish dress, and fake fangs. Was she taking Elizabeth's place? Well, at least she was in the spirit of the season.

"Yus! I shall show you how to be a proper Saber, you fool emperor," Elizabeth said with supreme confidence.

"Hah." Nero scoffed. She didn't seem impressed.

"At least I can out-Lancer you any day, Elizabeth," Tamamo said smugly.

"What? That's not even a proper lance!" Elizabeth said, pointing at the parasol Tamamo was holding.

"It's no worse than your microphone."

Hakuno decided to leave them to it, and look at the others.

"Artoria Pendragon reporting for service!" Artoria said, and even saluted.

Hakuno was a little startled. "Uh... huh... and you are a...?"

"[Archer](https://varewulf.files.wordpress.com/2018/10/artoria_archer_1.png)!"

"With a water-gun?"

"It has holy water. Tactical." Artoria seemed very eager about this. And might have been watching too many action movies. She was even holding the water-gun kinda like a rifle. But they were supposed to be fighting a bunch of undead, so she might be right about the holy water. Though exactly _where_ she had found holy water was a different matter. Maybe it was better not to ask.

There was another person who was clearly eager, but trying to hide it, also present.

"[I'm a Rider](https://varewulf.files.wordpress.com/2018/10/mordredrider4.png)," Mordred said before Hakuno could even ask.

"Right..." Hakuno looked at him, and the surfboard he was holding. "I don't think there's going to be a lot of water to ride in there," she pointed out.

Mordred blushed. "W-well, everyone else was going like this, so..." he mumbled.

Not everyone.

"I'm not sure why I need to put on glasses [to be a Berserker](https://varewulf.files.wordpress.com/2018/10/mhxalter1.png)," Artoria Alter (aka Salter) said.

Hakuno knew better than to say ' _because it makes you look cute_ ' out loud. "I see you're not sticking to the theme," she said instead.

"Absolutely not. I quite like this coat, I'll have you know," Salter said. It looked nice and comfy, but between that and the thick scarf it kinda looked like she had deliberately dressed to look as little like the regular Artoria as possible.

"Mum, mum, look at me!" said an excited little voice. A late arrival was coming, along with two escorts. "Do I look good?!" Altera asked, dressed as a little santa ([like so](https://varewulf.files.wordpress.com/2018/10/santa-altera.png), but smaller, and with a cap), and riding a robotic sheep the others had made for her. Hakuno didn't have the heart to tell her she was dressed for the wrong season. Especially considering the others present were even worse.

"You're adorable, sweetie," Hakuno said, and patted Altera's head. She wasn't sure what class Altera was meant to be. Rider, maybe, considering the sheep? The important part was that she had fun. It was her very first Halloween after all.

Along with her came the two Jeannes, who had actually dressed up appropriately as a couple of witches. Regular Jeanne was wearing a typical black attire, complete with a pointy hat, and a broom instead of banner pole. Jeanne Alter's outfit was identical, except it was white. Apparently that had been Jalter's idea, as they were supposed to dress as something they were not. Neither of them had bothered with a class change, and had instead been helping Hakuno set up the event. So Hakuno had already seen their costumes earlier that day.

It seemed like everything was ready to go. Though there was one thing that hadn't escaped Hakuno's notice.

"So no one wanted to be an Assassin?" she asked the group.

Silence.

Eventually broken by Salter: "Well, I was thinking the boy-"

"Daddy, you promised!" Mordred said quickly, cutting Salter off.

Salter looked amused rather than annoyed at the interruption. "Would it really be worse than what you're wearing now?" she asked with a smirk.

"Yes!"

While curious, Hakuno figured it was again best not to ask.

Onto the task at hand, the grand quest. Before the heroes stood a large, haunted castle, filled to the brim with the undead, and hiding a legendary treasure. So it was up to the seven intrepid heroes-

"Mum, is it going to be scary?" Altera asked, tugging at Hakuno's cloak. "I don't like scary."

Hakuno had been prepared for something like that. "Don't worry, sweetie," she said, and crouched down to her level. "We can go trick-or-treating instead. That won't be scary. And you'll get candy." Most everyone around the city should be in the spirit, or at least willing to go along with things. For the children, and all that.

Altera gasped. "Candy..." she whispered in an awed tone.

There was no way Hakuno was going inside that castle either. She didn't know everything that was going to happen, but she knew enough to know better than to risk it.

And so the six intrepid heroes-

"I'd rather have candy too," Salter said, and walked away from the others.

"Uh..." Hakuno blinked.

"Daddy?" Mordred called out.

"You have fun, son," Salter said, and smiled at him. "I'll be rooting for you. Show us you have what it takes to be a true king."

Mordred seemed to inflate. "Yes, daddy! I'll make you proud!" He beamed. Salter's charisma was strong.

Hakuno leaned over to Jalter. "Is it going to work with just five?" she asked in a hushed tone.

"Should be fine," Jalter replied. Though maybe her wicked smile should have been a cause for concern.

And so it was up to the five intrepid heroes to brave the castle, slay the undead, and find the treasure. Good luck to all!

"You can go with the trick-or-treaters, Jeanne," Jalter said in an uncharacteristically sweet tone. "Don't worry. I'll make sure our heroes have a fun time~."

"Ye, come with us, auntie Jeanne!" Altera said, tugging at Jeanne's skirt.

Jeanne appeared hesitant, but in the end went with Hakuno, Altera, and Salter. Salter didn't exactly have what Hakuno would deem a Halloween costume, but she doubted that anyone would dare say no if she asked them for candy.

"Are you sure it's okay to grant my Alter the power and authority to manage the event?" Jeanne asked Hakuno.

Jalter had volunteered to be the 'game master', so to speak. Overseeing the event, keeping track of the heroes, and managing the undead. Considering her hobby of writing stories, and her history as a leader, she seemed like a good fit. Though some, like Jeanne, were a bit concerned about her anti-hero nature.

"It should be fine," Hakuno said. "It only extends to the castle, after all." They had been able to set things up so that Jalter would get admin access to the Moon Cell's functions, but only within the designated area. It was still a lot of power, but Hakuno had decided to trust her with that. "What's the worst that could happen?"

* * *

The five heroes made their way inside. Not really encountering much difficulty as they progressed.

"Hyah!" Elizabeth shouted as she swung her sword at a skeleton. Didn't help much that they were resistant to piercing damage when she basically swung the sword like a club, striking down at the shoulder, and through the whole body.

"No grace," Nero said, making sure Elizabeth was within ear shot.

"Wha- that's exactly how _you_ do it!" Elizabeth said, her tail shooting into the air like a displeased cat. "I've seen the way you just wildly swing about."

"Everything I do is with precision," Nero said. "Like so." She raised her arm, and shot forth a blade of flame, cutting down a line of undead. "Umu~!"

"I think I'm getting the hang of this..." Tamamo mumbled. She shoved her parasol into a zombie's torso, and snapped it open, sending the body flying. It knocked over a couple of others as it went. "Strike~!"

There were undead everywhere. Skeletons, zombies, even a few wights. Basically anywhere you struck, you were guaranteed to hit something. But in spite of their numbers they weren't posing much of a threat.

Artoria was leaping around, ducking and rolling, as she fired her water-gun at anything that got close. The holy water was working well. None of her targets could withstand more than a single hit before falling apart. Though it looked a bit silly how she was clearly trying to mimic the action heroes of the movies she had been watching. The ducking and rolling seemed especially unnecessary, as even the wights weren't moving that fast.

Mordred was conserving mana for now. A surfboard strengthened for a heroic spirit worked well enough as a blunt weapon. He had a feeling that Jalter had more up her sleeve than just this. So it was best to be cautious.

* * *

Jalter was monitoring the situation with a smile on her face. Everything was going according to plan. The heroes were having an easy time, which was exactly what she wanted. To lull them into a false sense of security.

They were heading up to the second floor now, so it was probably time to throw something a little more challenging at them. She was sure they would be able to defeat it. In fact, she was counting on it.

* * *

Until now the five of them had basically just been working on their own, not together. Sure, they were technically on the same team, but there hadn't been anything that required teamwork.

But as they got to the top of the first set of stairs, they could hear a rumbling. It was getting closer. And suddenly something burst through a wall in front of them, sending stone and brickwork flying in all direction.

Elizabeth quickly hid behind her shield, Nero raised a magic barrier, Tamamo opened her parasol, Artoria ducked behind Tamamo's parasol, and Mordred hid behind his surfboard.

They could hear something growling, and once they looked, they saw a large undead minotaur standing there, holding a giant axe. It was probably bigger than all of Elizabeth.

And since Elizabeth was closest, it swung at her first. Instead of ducking out of the way, she took the hit on the shield, which caused the shock to run through her whole body. The floor cracked beneath her.

As the minotaur got ready to swing a second time, it suddenly got a faceful of fire. "Umu~, finally something big!" Nero said, and charged forward.

"Hey, Casters are supposed to stay back, you fool!" Tamamo shouted, and charged after Nero. Part of her wanted to stay back too, but she wasn't about to lose to Nero.

Artoria actually thought of the team, and provided cover fire for them. The splashes of holy water causing the minotaur to stagger a bit.

Elizabeth was slowly getting up on her trembling legs. Taking the blow instead of dodging had been a mistake. Physical fortitude had never been her strength, and that didn't seem to have improved much even with a class change.

Meanwhile Mordred figured it was about time to let loose a little. Sure, there wasn't any water here, but with a bit of mana, he could make his own. So with a grin on his face, he surfed through the air on a small wave, and crashed right into the minotaur's chest, toppling it over.

So while it wasn't exactly a stellar example of teamwork, the five of them managed to take down the minotaur together. A quick cheer rose up.

* * *

From somewhere above Jalter was still monitoring them. Her smile was a bit wider than before. She assumed, or at least hoped, that they would be a bit overconfident now that they had defeated the minotaur so easily.

The rest of the floor would proceed much the same as the last, just with slightly larger skeletons, and some hounds that would occasionally rush them. Stuff to make it feel like they were doing better, even if the difficulty wasn't particularly higher. Should still be a piece of cake for a quintet of heroic spirits.

On the next floor she would have another surprise ready for them. One that should be a true test. If they were as overconfident as she hoped, and had let their guards down again, it should prove quite entertaining.

* * *

Once the party got up the second set of stairs, two minotaurs stepped out of the shadows, one on either side of the wide hall.

As battle commenced, they didn't notice that these minotaurs were weaker than the first one, since they were too occupied with dealing with two of them. Then as soon as the second minotaur dropped, doors opened on either side, and a horde of skeletons sprung forth. These ones were wearing armour, and were faster, but they still went down quickly.

The heroes examined the rooms the skeletons had come from, but they were empty, and led nowhere. Seemed like they had been literal skeleton closets. That left only the large double doors at the end of the hall.

Elizabeth decided to be cool, and kicked the doors open. They flew open so easily that she nearly stumbled and fell forwards. She had expected them to be a little weightier than that. But maybe it made her look even stronger than she was. She was okay with that.

The room inside was completely dark, though the light from the hallway did show some outlines that suggested it was not empty.

The doors slammed shut behind them once all five were inside. It seemed like they were now trapped in this vast, dark room. But before they could try to open the door again, two blue lights flicked on further into the room. They started moving, and suddenly the whole room lit up. Revealing a giant skeletal dragon. The blue lights were the eyes in the sockets of its skull. It let out a loud roar, even though it clearly had no lungs with which to draw the air.

"Leave it to me!" Nero said, yet again charging forth.

Elizabeth tackled her just before a large skeletal leg stepped on her. "Didn't you hear that Casters are supposed to stay back?" she hissed. "You're too squishy now."

"I've always been squishy, umu," Nero said.

"I don't think stabbing that is going to be enough," Tamamo said off to their side. "Do Lancers have any special abilities?"

"Every Servant is different!" Elizabeth said, annoyed. "It's not like I can do everything Karna can, for instance!"

"That's for certain," Tamamo said without missing a beat.

"I don't like your tone!" Elizabeth was tempted to attack Tamamo, but was distracted by the dragon trying to squish them again.

Elizabeth and Nero rolled out of the way in separate directions.

"Take this!" Nero shouted, launching more fire at the dragon.

As the thing was about to make yet another attempt at squishing Nero, Mordred came flying out of nowhere, and rammed his surfboard right into the dragon's skull. "Yeah, that's what I'm talking about!" he yelled.

Meanwhile Artoria had decided it was best to ignore the others, and stayed to the dragon's side, firing at it continuously, and reloading when necessary. Several empty yellow canisters were rolling along the floor. The dragon tried tail-swiping her, but she jumped over it. It had to do better than that.

The dragon appeared to have had enough of all of them. Until now it had been lying on the ground, swiping at anyone who got too close, but now it got up on all four. It spread its bony wings, and with another loud, ear-ringing roar it generated a shockwave with enough force to push all the heroes back. Mordred being thrown all the way against the wall as he was still airborne.

The ceiling wasn't high enough for the undead beast to fly, but it proved to be faster than it looked, using the force of its wings to turn and move at increased bursts. The air pressure from the wings moving made it hard to approach.

"It's all bones, how is it even doing that?!" Elizabeth complained.

"Magic," Tamamo said with a shrug.

"I hate magic," Elizabeth grumbled.

"Know fear, fell beast! For today you face the greatest Emperor Rome has ever had!" Nero was really getting into it, and charged back in with fire balls and blades flying. The amount of mana she was literally burning was ridiculous.

"And the true heir to the throne of England!" Mordred yelled, again flying in on his magic surfboard.

Artoria looked up. "Excuse me?" she said, but no one heard.

Mordred swung his sword down on the dragon's neck. Maybe if he had still been a Saber that would have had enough force to decapitate it. Maybe not. But as things were right now, it only made the dragon angrier.

Elizabeth and Tamamo had little choice but to join the fray.

* * *

Eventually the bone dragon fell, and the heroes moved on up the final set of stairs.

Jalter might have been disappointed that they beat the dragon, if she wasn't so excited for what was going to happen next. Her grin went from ear to ear.

There were no more undead to fight, and the heroes made it into the treasure room. It looked like you would expect from a grand, old, haunted castle. Piles of gold, works of art, jewelled treasures. And at the other end of the room, the clearly highlighted centrepiece: Five large treasure chests. Each with the symbol for a Servant class on it, to match the five heroes.

Jalter felt positively giddy. "They think it's over," she said to no one in particular, and giggled.

She had fought hard to maintain her composure when Hakuno had brought up how there wasn't an Assassin in the group. Because there was an Assassin. She just wasn't on the heroes' side.

"You're up," she said.

Two red eyes shone from the shadows. "Aye."

* * *

"Hah! Easy!" Elizabeth said, puffing her chest out proudly.

"Umu!" Nero agreed.

"But what could be in these chests that would be of value to us?" Tamamo asked.

"Eh, who cares," Mordred said. His cautious attitude from the start was completely gone. "It's the journey that matters, and getting here was a lot of fun!"

Suddenly there was a yell from above.

"NAE KING! NAE QUIN! NAE LAIRD! NAE MASTER! NANE! SHALL! PASS!!!"

And [someone](https://varewulf.files.wordpress.com/2018/10/scathachassassinart.png) landed with a smash in the middle of the group, sending everyone flying.

* * *

"Trick or treat!"

Altera's candy bucket was filling up quickly as they moved through the streets. It was in the shape of little carved pumpkin with a happy face. Hakuno had told her it was okay to have a little along the way, but the girl had insisted she was saving it all for when they got home. The robot sheep was carrying a backup bucket shaped like a fat bat just in case.

They had seen a bunch of other little trick-or-treaters walking about too. The variety of costumes was endearing, and definitely very spooky.

Meanwhile Salter was carrying around a regular 10 litre bucket, which was also filling up at a steady rate. Not a single person dared turn her down.

Suddenly Jeanne had a strange sensation. She glanced back in the direction of the castle. "Hey..."

"Hm?" Hakuno looked over at her.

"Do you hear anything? Like screaming?" Jeanne asked.

Hakuno perked her ears up, and listened. "Nope, can't hear a thing."

**Author's Note:**

> Some notes:
> 
> To not leave people too curious, Salter had suggested to Mordred that he could dress as Jack the Ripper to be the party's Assassin, though Mordred had vehemently refused.
> 
> Jalter as a scheming, sadistic GM was much too fun of an idea to pass up.
> 
> Including Scáthach was not originally intended, but as I was writing, I noticed the lack of any Assassin in the group. So I went through the list of what Assassins were in FGO, to see if any of my current characters had an alternate version that was an Assassin. While both Artoria and Tamamo do, I already had something else for them. Seeing Scáthach gave me an idea, though. With everyone else I've added, why not also the angry Scottish woman? :3


End file.
